“Another younger man was already standing in the same area with a female companion.

“At Wigan, two older men barged onto the service and entered into a racist conversation with the man and woman before one of the older men began directing abusive, racist comments at the victim.”

Officers believe the man in the images could have vital information about what happened and urge him or anyone who recognises him to come forward to assist officers with their enquiries.

Anyone with information is asked to contact British Transport Police on, or text 61016, quoting reference PSUB/B6 of 14/10/2015. Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.